1. Field of the Invention
The present invention relates to a network connection system for making it possible to connect to a local network, etc., from a remote location.
2. Description of the Related Art
In recent years, the variety of working styles of workers has been increasing in cooperation with the widespread use of Internet connection environment. For example, so-called telecommuting-type working style for the worker to work at home while belonging to an enterprise is easily accepted, because development of remote access service (RAS) technology for accessing a local area network in an enterprise via a network shared by different users, such as the Internet and a public telephone network, from a remote location of user's home, etc., has moved forward.
In such a remote access service, it is the common practice to perform authentication on the local network side based on the user name and the password previously registered in the local network and encrypt traffic after authentication on the network (midway network) between the remote location and the accessed local network to prevent information used in the enterprise from being freely referenced.
JP-A-Hei. 8-235114 discloses an art for each terminal to acquire information required for connecting to a server from an intermediate server for the purpose of providing a system for enabling even a terminal not holding user authentication information of a plurality of servers to access the servers and managing collectively charging for the servers.
However, in the remote access service in the related art described above, the traffic after authentication is encrypted, but authentication information of the user name, etc., is distributed as it is. Therefore, if the user name is illegally gained in a midway network, it is made possible to make unauthorized access wherein the illegally gained user name is sent to the local network side for attacking at random as the password.